[Drake] T4XC: where is C103 and it's friends?

[fkamp@comcast.com]

K6jek@aol.com wrote:

> I'm having a devil of a time locating parts in my T4XC.  Is there a service
> manual of some sort I can use to find things like C103 (.005 audio coupling
> capacitor)?  Parts aren't labeled on the PC boards, the interconnects disappear
> into serpentine bundles.  The colors have faded to beige.
>
> BTW.  Has anyone improved the SSB audio on a T4XC?  K1JJ made the AM audio
> terrific and documented the mods.  But the SSB audio, at least mine, sounds
> squeakier than it needs to even allowing for a 2.4Khz filter.   The reason I'm
> tracking down C103 and C113 and C108 is to see if opening them up a bit from .005
> might open the T4XC SSB audio up just a touch at the low end.

My T4XCs audio on SSB was a little squeeky too at one time.  It was due to the
carrier oscillator being off frequency.  Once that was fixed it sounded just fine.

You might want to verify that the transmitter is working to spec before installing
non spec parts.

As for finding parts, I have always searched for them the hard way.  In some cases
the schematic indicates if they are in unusual places, like the product detector
diodes located inside the coil can, but not always.

Regards,
Frank Kamp
K5DKZ